Re-assigning all objects from on role to another in PostgreSQL

From time to time it might be required to move objects (tables, indexes, whatever) from one user to another user in a database system. You could do that by dumping all the objects with pg_dump and then load it to the target user. But there are other solutions which are faster than that. Lets go.

Obviously we need two users when we want to move objects from one user to another (actually it is not really moving the objects but more about changing the ownership):